Microbial bioavailability regulates organic matter preservation in marine sediments
Open Access
- 20 February 2013
- journal article
- Published by Copernicus GmbH in Biogeosciences (online)
- Vol. 10 (2), 1131-1141
- https://doi.org/10.5194/bg-10-1131-2013
Abstract
Burial of organic matter (OM) plays an important role in marine sediments, linking the short-term, biological carbon cycle with the long-term, geological subsurface cycle. It is well established that low-oxygen conditions promote organic carbon burial in marine sediments. However, the mechanism remains enigmatic. Here we report biochemical quality, microbial degradability, OM preservation and accumulation along an oxygen gradient in the Indian Ocean. Our results show that more OM, with biochemically higher quality, accumulates under low oxygen conditions. Nevertheless, microbial degradability does not correlate with the biochemical quality of OM. This decoupling of OM biochemical quality and microbial degradability, or bioavailability, violates the ruling paradigm that higher quality implies higher microbial processing. The inhibition of bacterial OM remineralisation may play an important role in the burial of organic matter in marine sediments and formation of oil source rocks.Keywords
This publication has 61 references indexed in Scilit:
- Global Patterns and Predictions of Seafloor Biomass Using Random ForestsPLOS ONE, 2010
- Benthic biological and biogeochemical patterns and processes across an oxygen minimum zone (Pakistan margin, NE Arabian Sea)Deep Sea Research Part II: Topical Studies in Oceanography, 2009
- Sedimentary pigments on the Pakistan margin: Controlling factors and organic matter dynamicsDeep Sea Research Part II: Topical Studies in Oceanography, 2009
- Oxygen and organic matter thresholds for benthic faunal activity on the Pakistan margin oxygen minimum zone (700–1100m)Deep Sea Research Part II: Topical Studies in Oceanography, 2009
- Macrofaunal communities and sediment structure across the Pakistan margin Oxygen Minimum Zone, North-East Arabian SeaDeep Sea Research Part II: Topical Studies in Oceanography, 2009
- Faunal responses to oxygen gradients on the Pakistan margin: A comparison of foraminiferans, macrofauna and megafaunaDeep Sea Research Part II: Topical Studies in Oceanography, 2009
- Amino acid biogeochemistry and organic matter degradation state across the Pakistan margin oxygen minimum zoneDeep Sea Research Part II: Topical Studies in Oceanography, 2009
- Carbon cycling in a continental margin sediment: contrasts between organic matter characteristics and remineralization rates and pathwaysEstuarine, Coastal and Shelf Science, 2003
- Possible influence of Zoophycos bioturbation on radiocarbon dating and environmental interpretationMarine Micropaleontology, 2002
- Annual in situ carbon dioxide and oxygen flux across a subtidal marine sedimentEstuarine, Coastal and Shelf Science, 1981